CA1327641C - Mobile transmitter/receiver - Google Patents
Mobile transmitter/receiverInfo
- Publication number
- CA1327641C CA1327641C CA000588228A CA588228A CA1327641C CA 1327641 C CA1327641 C CA 1327641C CA 000588228 A CA000588228 A CA 000588228A CA 588228 A CA588228 A CA 588228A CA 1327641 C CA1327641 C CA 1327641C
- Authority
- CA
- Canada
- Prior art keywords
- receiver
- information
- location
- data storage
- receivers
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired - Fee Related
Links
Classifications
-
- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04W—WIRELESS COMMUNICATION NETWORKS
- H04W64/00—Locating users or terminals or network equipment for network management purposes, e.g. mobility management
-
- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04W—WIRELESS COMMUNICATION NETWORKS
- H04W88/00—Devices specially adapted for wireless communication networks, e.g. terminals, base stations or access point devices
- H04W88/02—Terminal devices
Abstract
ABSTRACT
A mobile transmitter/receiver is for use in a communication system comprising a plurality of fixed transmitters/receivers located at spaced apart positions in a terrestial area, each fixed transmitter/receiver operating on one or more of a plurality of radio frequency channels. The mobile transmitter/receiver comprises: a transmitting/receiving section for transmitting information to and receiving information from the fixed transmitters/receivers; a location determining section for receiving signals from the fixed transmitters/receivers for determining the location of the mobile transmitter/receiver within the communication system, data storage for storing information relating to radio communication paths from all locations in the area to the fixed transmitters/receivers; a selecting section for determining from the location of the mobile transmitter/receiver determined by the location determining section and the information stored in the data storage a selected one of said communication paths;
and a conditioning section for conditioning the transmitting/receiving section in accordance with information stored in the data storage relating to the selected communication path.
A mobile transmitter/receiver is for use in a communication system comprising a plurality of fixed transmitters/receivers located at spaced apart positions in a terrestial area, each fixed transmitter/receiver operating on one or more of a plurality of radio frequency channels. The mobile transmitter/receiver comprises: a transmitting/receiving section for transmitting information to and receiving information from the fixed transmitters/receivers; a location determining section for receiving signals from the fixed transmitters/receivers for determining the location of the mobile transmitter/receiver within the communication system, data storage for storing information relating to radio communication paths from all locations in the area to the fixed transmitters/receivers; a selecting section for determining from the location of the mobile transmitter/receiver determined by the location determining section and the information stored in the data storage a selected one of said communication paths;
and a conditioning section for conditioning the transmitting/receiving section in accordance with information stored in the data storage relating to the selected communication path.
Description
MOBILE TRANSMITTER/R~OE IVER
This invention relates to mobile transmittersl receivers for use in communication systems, for example, for determining the correct and most effective communication route or path between mobile transmitters/
receivers and fixed transmitters/receivers. The present invention also seeks to ensure the use of a correct technological standard, i.e. the correct frequency, modulation and other characteristics appropriate to the required communication path. -It is relatively easy to arrange for speech or -~ata to be addressed and routed to a specific location which may be, for example, a telex machine in a particular room in a building or an operator positioned in an enguiry office. Setting up a communication path to a mobile termlnal is more difficult.
Mobile terminals, whether vehicular or personal, are liable to be used in a large variety of locations so communication is normally maintained through the use of radio channels. If the radio system is complex, either thQ mobile terminal operator USQS his knowledge of the radio system coupled with his assessment of his own location to dacide which communication path to set up, `~
2S or some automatic means must be provided.
If the mobile terminal is reguired to move over a large area a proportionately large number of radio sites are necessary. To provide for a large number of vehicles a considerable number of radio channels are needed, and all these channels must be connected in some logical way into a network if the system is to function as a coherent whole.
Very complex and sophisticated means have been ~
developed to enable mobile termlnals to address and ` -route messages through such systems, for example, twenty-one 8 kbit/sec data channels are used in the TACS
cellular system for this purpose alone, besides the additional supervision and monitoring data carried on message channels. This system is fundamentally a compromise, since the mobile terminal has to sense its radio environment so that it can make a decision as to which ra~io path is appropriate for tbat location. The vagaries oi radio propagation cause errors in this process, particularly in an area where the radio signals from two or more sites are approximately equal in ~
strength. Also the signals from a distant transmitter -in a good location may at times be stronger than those from a local station, though the latter wlll usually be 15 more consistently satisfactory. -~
Communication systems currently under consideration may need to span continents with numerous ~ ;
individual communication systems being the --responsibility of one or more national operators. In these circumstances the foregoing methods ~ addressing and routing message become very unwieldy. They are also liable to take up a disproportlonate amount of time in relation to the message itself. Most routine data messages occupy a communication channel for only a fraction of the time taken by a complex network to set up the communicatlon path. ~-The radio channels may use parts of the radio spQctrum with propagation characteristics which vary slgnlficantly with temperature, moisture, time, etc. and in such circumstances the automatlc sensing methods could prove impracticable.
The present lnvention seek~ to provide a mobile transmitter/receiver which employs a location infrastructure to provide location information to the " - 1 327641 .
mobile transmitter/receiver thus eliminating most of the problems discussed above.
According to one aspect of the present invention there is provided a mobile transmitter/receiver for use in a communication system comprising a plurality of fixed transmitters/receivers located at spaced apart positions in a terrestrial area, each fixed transmitter/receiver operating on one or more of a plurality of radio frequency channels, and locating 10 means, the mobile transmitter/receiver comprising: -transmitting/receiving means for transmitting information to and receiving information from the fixed transmitters/receivers; location determining means for receiving signals from the locating means for determining the location of the mobile transmitter/receiver within the communication system;
data storage means for storing information relating to radio communication paths from all locations in the area to the fixed transmitters/receivers; selecting ~eans for determining from the location of the mobile transmitter/rQceiver determined by the location determining means and the information stored in the data ~torage means, a selected one of said communication paths; and conditioninq means for providing the transmitting/rQceiving means with information stored in ~he data ~torage means relating to the selectQd co~unication path.
Preferably the mobile transmitter/receiver includes means ~or conditioning the transmittingtreceiving means in accordance with power and/or sensitivity information from the data storage means relating to the selected communication path.
Additionally or alternatively the mobile transmitter/rQceiver may include means for directing a radio bQ~ from the transmitting/receiving means in 4 1 32764~
accordance with information from the data storage means relating to the direction of the selected communication path.
The data storage means may include a look-up table.
Accordinq to a further aspect of the present invention there is provided a communication system comprising: a plurality of fixed tran3mitters/receivers located at spaced apart positions in a terrestrial area, each fixed transmitter/receiver operating on one or more of a plurality of radio frequency channels; locating means; and a plurality of mobile transmitters/receivers each comprising transmitting/receiving means for transmitting information to and receiving information from the fixed transmitters/receivers, location determining means for receiving signals from the locating means for determining the location of the ~obile transmitter/receiver within the communication systemr data storage means for storing information relating to radio communication paths from all locations in the area to the fixed transmitters/receivers, selacting ~eans for determining ~rom the location of the Dobila transmitter/receiver determined by the location datermining means and the information stored in the data ~torage means, a selQcted one or said communication pat~s, and conditioning means for providing the transmitting/ receiving means with information stored in the data storagQ means relating to the selected coJounication path.
The invQntion i8 illustrated, merely by way of ~xample, in th~ accompanying drawings, in which:-Figure 1 is a schematic diagram of a manualco~munication system;
',", ~' :'.
- ~e~ ., Figure 2 is a schematic diagram of an automatic communication system:
Figures 3a and 3b are diagrams illustrating the operation of a communication system using a mobile transmitter/receiver according to the present invention;
and Figure 4 is a block diagram of a mobile transmitter!receiver according to the present invention.
Two-way communication with a mobile transmitter/
receiver or terminal is generally achieved through the medium of one or a plurality of short-range radio frequencies (hereinafter referred to as channels) selected from the thousands that may be used. Different channels are used in di~ferent locations which may be only a short distance apart. Sometimes completely different channels are used for completely different communication purposes at the same location, for example the requirements of a speech channel and tbose for a data channel are different. Another consideration is that one channel to the mobile terminal may he used exclu~lvely for one operational purpose, whilst an entirely separate channel or channels may be used to the same mobile terminal for different operational purposes.
To establish a communication path to a mobile ~ `
terminal, t~o fundamental requlrements must be met:
1. Th~ correct ra~io freguency must be known and al~o the correct modulatlon and technological standards;
This invention relates to mobile transmittersl receivers for use in communication systems, for example, for determining the correct and most effective communication route or path between mobile transmitters/
receivers and fixed transmitters/receivers. The present invention also seeks to ensure the use of a correct technological standard, i.e. the correct frequency, modulation and other characteristics appropriate to the required communication path. -It is relatively easy to arrange for speech or -~ata to be addressed and routed to a specific location which may be, for example, a telex machine in a particular room in a building or an operator positioned in an enguiry office. Setting up a communication path to a mobile termlnal is more difficult.
Mobile terminals, whether vehicular or personal, are liable to be used in a large variety of locations so communication is normally maintained through the use of radio channels. If the radio system is complex, either thQ mobile terminal operator USQS his knowledge of the radio system coupled with his assessment of his own location to dacide which communication path to set up, `~
2S or some automatic means must be provided.
If the mobile terminal is reguired to move over a large area a proportionately large number of radio sites are necessary. To provide for a large number of vehicles a considerable number of radio channels are needed, and all these channels must be connected in some logical way into a network if the system is to function as a coherent whole.
Very complex and sophisticated means have been ~
developed to enable mobile termlnals to address and ` -route messages through such systems, for example, twenty-one 8 kbit/sec data channels are used in the TACS
cellular system for this purpose alone, besides the additional supervision and monitoring data carried on message channels. This system is fundamentally a compromise, since the mobile terminal has to sense its radio environment so that it can make a decision as to which ra~io path is appropriate for tbat location. The vagaries oi radio propagation cause errors in this process, particularly in an area where the radio signals from two or more sites are approximately equal in ~
strength. Also the signals from a distant transmitter -in a good location may at times be stronger than those from a local station, though the latter wlll usually be 15 more consistently satisfactory. -~
Communication systems currently under consideration may need to span continents with numerous ~ ;
individual communication systems being the --responsibility of one or more national operators. In these circumstances the foregoing methods ~ addressing and routing message become very unwieldy. They are also liable to take up a disproportlonate amount of time in relation to the message itself. Most routine data messages occupy a communication channel for only a fraction of the time taken by a complex network to set up the communicatlon path. ~-The radio channels may use parts of the radio spQctrum with propagation characteristics which vary slgnlficantly with temperature, moisture, time, etc. and in such circumstances the automatlc sensing methods could prove impracticable.
The present lnvention seek~ to provide a mobile transmitter/receiver which employs a location infrastructure to provide location information to the " - 1 327641 .
mobile transmitter/receiver thus eliminating most of the problems discussed above.
According to one aspect of the present invention there is provided a mobile transmitter/receiver for use in a communication system comprising a plurality of fixed transmitters/receivers located at spaced apart positions in a terrestrial area, each fixed transmitter/receiver operating on one or more of a plurality of radio frequency channels, and locating 10 means, the mobile transmitter/receiver comprising: -transmitting/receiving means for transmitting information to and receiving information from the fixed transmitters/receivers; location determining means for receiving signals from the locating means for determining the location of the mobile transmitter/receiver within the communication system;
data storage means for storing information relating to radio communication paths from all locations in the area to the fixed transmitters/receivers; selecting ~eans for determining from the location of the mobile transmitter/rQceiver determined by the location determining means and the information stored in the data ~torage means, a selected one of said communication paths; and conditioninq means for providing the transmitting/rQceiving means with information stored in ~he data ~torage means relating to the selectQd co~unication path.
Preferably the mobile transmitter/receiver includes means ~or conditioning the transmittingtreceiving means in accordance with power and/or sensitivity information from the data storage means relating to the selected communication path.
Additionally or alternatively the mobile transmitter/rQceiver may include means for directing a radio bQ~ from the transmitting/receiving means in 4 1 32764~
accordance with information from the data storage means relating to the direction of the selected communication path.
The data storage means may include a look-up table.
Accordinq to a further aspect of the present invention there is provided a communication system comprising: a plurality of fixed tran3mitters/receivers located at spaced apart positions in a terrestrial area, each fixed transmitter/receiver operating on one or more of a plurality of radio frequency channels; locating means; and a plurality of mobile transmitters/receivers each comprising transmitting/receiving means for transmitting information to and receiving information from the fixed transmitters/receivers, location determining means for receiving signals from the locating means for determining the location of the ~obile transmitter/receiver within the communication systemr data storage means for storing information relating to radio communication paths from all locations in the area to the fixed transmitters/receivers, selacting ~eans for determining ~rom the location of the Dobila transmitter/receiver determined by the location datermining means and the information stored in the data ~torage means, a selQcted one or said communication pat~s, and conditioning means for providing the transmitting/ receiving means with information stored in the data storagQ means relating to the selected coJounication path.
The invQntion i8 illustrated, merely by way of ~xample, in th~ accompanying drawings, in which:-Figure 1 is a schematic diagram of a manualco~munication system;
',", ~' :'.
- ~e~ ., Figure 2 is a schematic diagram of an automatic communication system:
Figures 3a and 3b are diagrams illustrating the operation of a communication system using a mobile transmitter/receiver according to the present invention;
and Figure 4 is a block diagram of a mobile transmitter!receiver according to the present invention.
Two-way communication with a mobile transmitter/
receiver or terminal is generally achieved through the medium of one or a plurality of short-range radio frequencies (hereinafter referred to as channels) selected from the thousands that may be used. Different channels are used in di~ferent locations which may be only a short distance apart. Sometimes completely different channels are used for completely different communication purposes at the same location, for example the requirements of a speech channel and tbose for a data channel are different. Another consideration is that one channel to the mobile terminal may he used exclu~lvely for one operational purpose, whilst an entirely separate channel or channels may be used to the same mobile terminal for different operational purposes.
To establish a communication path to a mobile ~ `
terminal, t~o fundamental requlrements must be met:
1. Th~ correct ra~io freguency must be known and al~o the correct modulatlon and technological standards;
2. The location an~ address of t~e correct base statlon, l.e. the one wlth the be~t capability to access the moblle termlnal, must be known.
Flgure 1 shows a manual communication system having a radio ba~e station 7 coverlng an area whose boundary ls indlcated by a broken line 7' and a radio base statlon 8 whose boundary is indicated by a broken '. ~, , . ',' ... ..
line ~'. Each ra~io base station 7, 8 includes a respective fixed transmitter/receiver 9,10. The fixed transmitters/receivers are connected by respective land lines 11,12 to a base control 13 through which communication is made with base terminals (not shown).
The radio base station 7 uses a radio communication channel C34 and the radio base station ~ uses a radio communication channel C95. Thus a mobile transmitterl receiver or terminal 14 within the area covered by the radio base station 7 has to be tuned to the channel C94 and when within the area covered by the radio base station 8 has to be tuned to the channel C95.
The simplest method of settlng up a communication path using the system illustrated in Figure 1 requires the operator of the mobile terminal 14 to memorise or refer to a tabulated list to estahlish the correct radio channel or each location in which he finds himself.
~his necessitates frequent changes, particularly if the mobile terminal 14 is in a fast moving vehicle. If the ~-base control 13 is connected in tandem into a public _witched telephone network (PSTN) the operator of the mobile terminal will also have to use an appropriate telQphone code for routing and addressinq his calls to a particular base terminal, e.g. a telephone. In effect, 2~ apart from identifying the ba_e terminal for ` ~
communication the operator ~ill have to define the ; ~ `
communicatlon path appropriate to this purpoQe.
Raving done so there are several management methodQ of initiating a call from a base terminal to _uch a mobile terminal~ The simplest is to maintain a manual record of the most recent area of operation of the mohile terminal so that the same channel can be used for communication. R~gular routine calls may be used to ensure the frequent updating of this manual record.
`:~
~ 32764~
Another method is to cycle the call from the base terminal through successive base stations using the appropriate channel in each case to determine in which area the mobile terminal is operating, if at all.
There are many varia'ions of these methods of originating a call to a mobile terminal from a base terminal, but they all invariably take up some channel capacity for setting up purposes and thus reduce the channel capacity for conveying useful communicatlon information.
It is also evident that, whilst the manual method may be acceptable with relatively uncomplicated small overall area networks, it becomes impractical for large area networks which are invariably complex, and may use many hundreds of radio channels from a large number of fixed base stations whose areas of coverage may also be sectorised.
Figure 2 illustrates a very simple communication system for automatically routing messages through the fixed base stations in the best location for communicating with the required mobile terminal.
A specific control channel C1 is reserved for setting-up purposes. The mobile terminal 14 is always tune~ to this control channel when it is inactive and automatic regular calls are made to all base stations and ackno~ledgad by those near enough to be in communication. The strongest radlo signal received on the control channel C1 (in the example shown, the slgnal from the ~ase station 7) is used to determine the -corr~ct channel C94 for the mobile terminal to use.
After moving to a new location the radio signal received on the control channel C1 from the base station 8 may become stronger than that from the others, and so "hand-over" to the base station a occurs and the message ;: . .
' ' ~' ' -'-' "' ,~ ~ 1 327641 continues on channel C95 with only momentary interruption.
This system, however, becomes extremely complicated when a large number of channels are used from each base station. Also very small areas or "cells" of only a kilometre across are frequently used for personal radio communications, so frequent "hand-overs" and changes of freguency are necessary, thus causing each mobile terminal to occupy yet more control -channel time. Some networks have become so complex that multiple control channels are necessary, thus causing further complication.
Figures 3a, 3b and 4 are diagrams illustratlng the operation of a mobile communication system wherein a correct communication path within a network A ~Figure 3b) to and from a mobile transmitter/receiver or terminal Nnn7 according to the present invention is automatically determined. $he network A may operate in the u.h.f. radio band~ Each dot in Figure 3b represents a fixed base station, e.g. a fixed transmitter/receiver linked to a common control centre (not shown) or one cell of a cellular telaphone network such as AMP~ or $ACS. In a terrestial area covering a square with sides of 150km there will be approximately forty fixed base -~tations if they are based apart from each by 25km. In a cellular telephone network, for example, the fixed base stations or cells may be spaced apart by considerably less than 25km.
$he configuration and mode of communication of the 30 network A may be conventional and does not form part of ~`~
the present invention~ The communication system shown ln Figures 3a and 3~ determines the correct communication path between the mobile terminal MT17 and a control centre to w~lich the fixed base stations are ,'.,' .': .
,, :: ..
... ..
.. . ~, . ., ~ ,. .
connected and hence from t~e control centre to, for example, a public switche~ telephone network. Thus t~ere is provided a separate network B shown in Figure 3a which may operate on a low frequency radio band an~
S which serves for radio navigation and location purposes.
The terrestial area represented by Figure 3a is defined by four hyperbolic navigation transmitters 1 to 4, and is identical to the terrestial area covered by the networX A of Figure 3b. Whilst the networks A,~ are shown separately in Figures 3a and 3b, it will be appreciated that the mobile terminal within the terrestial area covered will be able to receive signals ~;
from both networks.
Figures 3a and 3b show the mobile terminal MT17 -located at map referance E,N. The mobile terminal MT17 has a navigational recei~er 30 (Figure 4) to derive positional information from the signals received from the transmitters 1 to 4. The navigational receiver produces a bit-coded positional signal representative of the location of the mobile terminal MT17 at map referencQ E,N. This posltional signal is used by a central processor, in con~unction with a data ~tore and look-up table 31 which is a database using any form of -magnetic or optical or other storage medium. The data ~tore and look-up tahle 31 contains pre-recorded information regarding communication paths from all locatlons to the basa stations of the networX A.
Posltional information from the navigation receiver is compare~ with the information stored in the data store 30 and look-up table 31 which then determines the most -appropriate communication path from the particular location of the mohile terminal to a base station. It is assumed from the example illustrated in Figure 3~
with the mobile termi~lal and map reference E,N that the 1 32764~
most appropriate communication path is to a base station 25 as opposed to ad;acent base stations 22,24 or 26 by virtue of being closest and there being no intermediate geographical or other obstacles. If there was an ohstacle, e~g. a hill hetween the mobile terminal MT17 and the base station 25, the data store and look-up table would contain information to indicate that, say, the base station 22 represented the most appropriate communication path.
The data store and look-up table 31 provides information to a channel selection unit 32, which tunes a transmitter/receiver section 33 of the mobile terminal to the or one of the channels on which the ~ase station 25 operates. The transmitter/receiver section 33 may be -capable of accessing a large variety of radio communication systems using various frequency bands, different modes of modulation, and be capable of conveying speech, data, facsimile information, etc.
The data store and look-up table also provides information la) about the appropriate power level the recei~er/transmitter section 33 should use when -communicatlng with the base station 25 and (b) if desired, about the sensitivity level to which the receiver/tran~mitter section 33 should be set to 25 minimise interference between signals received by the `~
mobile terminal at its particular location. This information is fed to a power andtor sensitivity selection unit 34 which appropriately conditlons the receiver/tran~mitter section 33. ~ -;
The data store and look-up table 31 also produces information about the relative direction of the mobile terminal Mn~7 from the base station 25 (it lies due east in Figure 3b). This information is fed to an aerial ;~
d1rect1on ~elect1on unlt 35 whlch control~ an aer1al of ... :' ' ,' :~ ' 11 1 32764~
the receiver/transmitter section 33 to steer t~e radio beam from the receiver/transmitter section 33 in an easterly dire~tion, in this example, towards the base station 25. Conventional electronic steering of a directional aerial may be used for this purpose.
Information from the data store and looX-up table may he sent to the base station 25 to condition the base station in a similar way to use the correct power setting and to direct its radio beam in the direction of the mobile terminal when communicating with it.
The mobile terminal MT17 will thus communicate with base station 25 to convey its identity, the correct power setting for the communication path, and the correct reverse direction from the base station to the mobile terminal. If the base statlon uses trunked radio channels tke choice of the appropriate channel may be made using any of the normal methods. The base station informs the common control centre of the availahility of ~ile terminal MT17 through this communication path.
Thus a Qll from a base terminal to the mobile terminal can be set up by the common control centre which containQ information relating to the communication path to the moblle terminal. The mobile terminal communicates ~ith the common control centre sufficiently 2~ freguently via appropriate base stations, so that the coNmon control centre contains up-to-date information as to the com~unication path to u~e from a base terminal to the mobile terminal. If the mobile terminal has moved to the area of a different base station of the same `-network, the common control centre will be aware of this, and any message from the base station to t~e -` -mobile terminal will be correctly routed within the network. ;
If a vehicle bo~md from London to Marseilles has - -thus been logged into a London network for the first part of its journey, it will need access to several other networks en route. Data will have been obtained from any appropriate Paris network and Lyons network and this data will be entered into the data store and look-up table 31 of the mobile terminal MT17. When the vehicle is approaching Paris, positional information - -determined by the mobile terminal, will ensure that the mobile terminal is correctly tuned to the Paris network and will ensure that the most appropriate communication paths are used as the mobile terminal moves through the Paris network. The same applies as the vehicle enters the Lyons network.
The communication between the mobile terminal and the base stations o~ all the networks may be automatic, i.e. without any human intervention. The system may thus be used to automatically track containers used for transporting goods along roads, canals or railways, etc.
It will be appreciated that any means may be used 20 to provide the mobile terminal wlth positional :
information. For example, a dead-reckoning method may be used. Once the location of the mobile terminal is knnwn, using pre-recorded and stored informatlon in the mobilQ terminal relating to all locations in the area of ;`
operation, and accessing this stored information using known data cross-referencing techniques (e.g. a so-called "look-up table"), enables access to any of a number of possible radio networks in any area, no matter how large. The invention can, thus, be used to 30 integrate a large number of local networks in a ~-continental area such as ~urope or North America. For example, positional information determined by the mobile terminal, will enable the data store and look-up table to condition the transmitter/receiver section 33 not ~ 32764~
only as to the snost appropriate communication path in any given communication network to use but also to the mode of communication of the given communication network within which the mobile terminal is located. In other words, the information stored in each mobile terminal will allow it to set the correct radio frequency ~channel), power, band width, mode of operation, etc. to its location and applies equally to speech, data, facsimile or other communication networks.
It will be appreciated that the mobile terminal can thus be precisely located in relation to the radio coverage pattern of the communication network. The necessary information regarding the network is stored in the mobile terminal in such a way that it can be accessed as soon as the location is determined. The positional information obtained is updated at suitable intervals so that the com~unication path is optimised as often as necessary to maintain a reliable communication path into the network during the entire course of the ~ourney of the mobile terminal.
In effQct, the present internal infrastructure det~ermining the addressing and routing of speech and/or data to and from mobile t~rminals is replaced in the pr~sent invention by a much more efficient and effective external infrastructure operating in an entirely different way. The information contained in the data ~tore and look-up table is prepared and. optimised beforehand, so that the correct communication path between the mobile terminal and the particular base ~tatlon iQ set up regardle~s of any vagaries in the radio conditions at the time.
Flgure 1 shows a manual communication system having a radio ba~e station 7 coverlng an area whose boundary ls indlcated by a broken line 7' and a radio base statlon 8 whose boundary is indicated by a broken '. ~, , . ',' ... ..
line ~'. Each ra~io base station 7, 8 includes a respective fixed transmitter/receiver 9,10. The fixed transmitters/receivers are connected by respective land lines 11,12 to a base control 13 through which communication is made with base terminals (not shown).
The radio base station 7 uses a radio communication channel C34 and the radio base station ~ uses a radio communication channel C95. Thus a mobile transmitterl receiver or terminal 14 within the area covered by the radio base station 7 has to be tuned to the channel C94 and when within the area covered by the radio base station 8 has to be tuned to the channel C95.
The simplest method of settlng up a communication path using the system illustrated in Figure 1 requires the operator of the mobile terminal 14 to memorise or refer to a tabulated list to estahlish the correct radio channel or each location in which he finds himself.
~his necessitates frequent changes, particularly if the mobile terminal 14 is in a fast moving vehicle. If the ~-base control 13 is connected in tandem into a public _witched telephone network (PSTN) the operator of the mobile terminal will also have to use an appropriate telQphone code for routing and addressinq his calls to a particular base terminal, e.g. a telephone. In effect, 2~ apart from identifying the ba_e terminal for ` ~
communication the operator ~ill have to define the ; ~ `
communicatlon path appropriate to this purpoQe.
Raving done so there are several management methodQ of initiating a call from a base terminal to _uch a mobile terminal~ The simplest is to maintain a manual record of the most recent area of operation of the mohile terminal so that the same channel can be used for communication. R~gular routine calls may be used to ensure the frequent updating of this manual record.
`:~
~ 32764~
Another method is to cycle the call from the base terminal through successive base stations using the appropriate channel in each case to determine in which area the mobile terminal is operating, if at all.
There are many varia'ions of these methods of originating a call to a mobile terminal from a base terminal, but they all invariably take up some channel capacity for setting up purposes and thus reduce the channel capacity for conveying useful communicatlon information.
It is also evident that, whilst the manual method may be acceptable with relatively uncomplicated small overall area networks, it becomes impractical for large area networks which are invariably complex, and may use many hundreds of radio channels from a large number of fixed base stations whose areas of coverage may also be sectorised.
Figure 2 illustrates a very simple communication system for automatically routing messages through the fixed base stations in the best location for communicating with the required mobile terminal.
A specific control channel C1 is reserved for setting-up purposes. The mobile terminal 14 is always tune~ to this control channel when it is inactive and automatic regular calls are made to all base stations and ackno~ledgad by those near enough to be in communication. The strongest radlo signal received on the control channel C1 (in the example shown, the slgnal from the ~ase station 7) is used to determine the -corr~ct channel C94 for the mobile terminal to use.
After moving to a new location the radio signal received on the control channel C1 from the base station 8 may become stronger than that from the others, and so "hand-over" to the base station a occurs and the message ;: . .
' ' ~' ' -'-' "' ,~ ~ 1 327641 continues on channel C95 with only momentary interruption.
This system, however, becomes extremely complicated when a large number of channels are used from each base station. Also very small areas or "cells" of only a kilometre across are frequently used for personal radio communications, so frequent "hand-overs" and changes of freguency are necessary, thus causing each mobile terminal to occupy yet more control -channel time. Some networks have become so complex that multiple control channels are necessary, thus causing further complication.
Figures 3a, 3b and 4 are diagrams illustratlng the operation of a mobile communication system wherein a correct communication path within a network A ~Figure 3b) to and from a mobile transmitter/receiver or terminal Nnn7 according to the present invention is automatically determined. $he network A may operate in the u.h.f. radio band~ Each dot in Figure 3b represents a fixed base station, e.g. a fixed transmitter/receiver linked to a common control centre (not shown) or one cell of a cellular telaphone network such as AMP~ or $ACS. In a terrestial area covering a square with sides of 150km there will be approximately forty fixed base -~tations if they are based apart from each by 25km. In a cellular telephone network, for example, the fixed base stations or cells may be spaced apart by considerably less than 25km.
$he configuration and mode of communication of the 30 network A may be conventional and does not form part of ~`~
the present invention~ The communication system shown ln Figures 3a and 3~ determines the correct communication path between the mobile terminal MT17 and a control centre to w~lich the fixed base stations are ,'.,' .': .
,, :: ..
... ..
.. . ~, . ., ~ ,. .
connected and hence from t~e control centre to, for example, a public switche~ telephone network. Thus t~ere is provided a separate network B shown in Figure 3a which may operate on a low frequency radio band an~
S which serves for radio navigation and location purposes.
The terrestial area represented by Figure 3a is defined by four hyperbolic navigation transmitters 1 to 4, and is identical to the terrestial area covered by the networX A of Figure 3b. Whilst the networks A,~ are shown separately in Figures 3a and 3b, it will be appreciated that the mobile terminal within the terrestial area covered will be able to receive signals ~;
from both networks.
Figures 3a and 3b show the mobile terminal MT17 -located at map referance E,N. The mobile terminal MT17 has a navigational recei~er 30 (Figure 4) to derive positional information from the signals received from the transmitters 1 to 4. The navigational receiver produces a bit-coded positional signal representative of the location of the mobile terminal MT17 at map referencQ E,N. This posltional signal is used by a central processor, in con~unction with a data ~tore and look-up table 31 which is a database using any form of -magnetic or optical or other storage medium. The data ~tore and look-up tahle 31 contains pre-recorded information regarding communication paths from all locatlons to the basa stations of the networX A.
Posltional information from the navigation receiver is compare~ with the information stored in the data store 30 and look-up table 31 which then determines the most -appropriate communication path from the particular location of the mohile terminal to a base station. It is assumed from the example illustrated in Figure 3~
with the mobile termi~lal and map reference E,N that the 1 32764~
most appropriate communication path is to a base station 25 as opposed to ad;acent base stations 22,24 or 26 by virtue of being closest and there being no intermediate geographical or other obstacles. If there was an ohstacle, e~g. a hill hetween the mobile terminal MT17 and the base station 25, the data store and look-up table would contain information to indicate that, say, the base station 22 represented the most appropriate communication path.
The data store and look-up table 31 provides information to a channel selection unit 32, which tunes a transmitter/receiver section 33 of the mobile terminal to the or one of the channels on which the ~ase station 25 operates. The transmitter/receiver section 33 may be -capable of accessing a large variety of radio communication systems using various frequency bands, different modes of modulation, and be capable of conveying speech, data, facsimile information, etc.
The data store and look-up table also provides information la) about the appropriate power level the recei~er/transmitter section 33 should use when -communicatlng with the base station 25 and (b) if desired, about the sensitivity level to which the receiver/tran~mitter section 33 should be set to 25 minimise interference between signals received by the `~
mobile terminal at its particular location. This information is fed to a power andtor sensitivity selection unit 34 which appropriately conditlons the receiver/tran~mitter section 33. ~ -;
The data store and look-up table 31 also produces information about the relative direction of the mobile terminal Mn~7 from the base station 25 (it lies due east in Figure 3b). This information is fed to an aerial ;~
d1rect1on ~elect1on unlt 35 whlch control~ an aer1al of ... :' ' ,' :~ ' 11 1 32764~
the receiver/transmitter section 33 to steer t~e radio beam from the receiver/transmitter section 33 in an easterly dire~tion, in this example, towards the base station 25. Conventional electronic steering of a directional aerial may be used for this purpose.
Information from the data store and looX-up table may he sent to the base station 25 to condition the base station in a similar way to use the correct power setting and to direct its radio beam in the direction of the mobile terminal when communicating with it.
The mobile terminal MT17 will thus communicate with base station 25 to convey its identity, the correct power setting for the communication path, and the correct reverse direction from the base station to the mobile terminal. If the base statlon uses trunked radio channels tke choice of the appropriate channel may be made using any of the normal methods. The base station informs the common control centre of the availahility of ~ile terminal MT17 through this communication path.
Thus a Qll from a base terminal to the mobile terminal can be set up by the common control centre which containQ information relating to the communication path to the moblle terminal. The mobile terminal communicates ~ith the common control centre sufficiently 2~ freguently via appropriate base stations, so that the coNmon control centre contains up-to-date information as to the com~unication path to u~e from a base terminal to the mobile terminal. If the mobile terminal has moved to the area of a different base station of the same `-network, the common control centre will be aware of this, and any message from the base station to t~e -` -mobile terminal will be correctly routed within the network. ;
If a vehicle bo~md from London to Marseilles has - -thus been logged into a London network for the first part of its journey, it will need access to several other networks en route. Data will have been obtained from any appropriate Paris network and Lyons network and this data will be entered into the data store and look-up table 31 of the mobile terminal MT17. When the vehicle is approaching Paris, positional information - -determined by the mobile terminal, will ensure that the mobile terminal is correctly tuned to the Paris network and will ensure that the most appropriate communication paths are used as the mobile terminal moves through the Paris network. The same applies as the vehicle enters the Lyons network.
The communication between the mobile terminal and the base stations o~ all the networks may be automatic, i.e. without any human intervention. The system may thus be used to automatically track containers used for transporting goods along roads, canals or railways, etc.
It will be appreciated that any means may be used 20 to provide the mobile terminal wlth positional :
information. For example, a dead-reckoning method may be used. Once the location of the mobile terminal is knnwn, using pre-recorded and stored informatlon in the mobilQ terminal relating to all locations in the area of ;`
operation, and accessing this stored information using known data cross-referencing techniques (e.g. a so-called "look-up table"), enables access to any of a number of possible radio networks in any area, no matter how large. The invention can, thus, be used to 30 integrate a large number of local networks in a ~-continental area such as ~urope or North America. For example, positional information determined by the mobile terminal, will enable the data store and look-up table to condition the transmitter/receiver section 33 not ~ 32764~
only as to the snost appropriate communication path in any given communication network to use but also to the mode of communication of the given communication network within which the mobile terminal is located. In other words, the information stored in each mobile terminal will allow it to set the correct radio frequency ~channel), power, band width, mode of operation, etc. to its location and applies equally to speech, data, facsimile or other communication networks.
It will be appreciated that the mobile terminal can thus be precisely located in relation to the radio coverage pattern of the communication network. The necessary information regarding the network is stored in the mobile terminal in such a way that it can be accessed as soon as the location is determined. The positional information obtained is updated at suitable intervals so that the com~unication path is optimised as often as necessary to maintain a reliable communication path into the network during the entire course of the ~ourney of the mobile terminal.
In effQct, the present internal infrastructure det~ermining the addressing and routing of speech and/or data to and from mobile t~rminals is replaced in the pr~sent invention by a much more efficient and effective external infrastructure operating in an entirely different way. The information contained in the data ~tore and look-up table is prepared and. optimised beforehand, so that the correct communication path between the mobile terminal and the particular base ~tatlon iQ set up regardle~s of any vagaries in the radio conditions at the time.
Claims (5)
1. A mobile transmitter/receiver for use in a communication system comprising a plurality of fixed transmitters/receivers located at spaced apart positions in a terrestrial area, each fixed transmitter/receiver operating on one or more of a plurality of radio frequency channels, and locating means, the mobile transmitter/receiver comprising: transmitting/receiving means for transmitting information to and receiving information from the fixed transmitters/receivers;
location determining means for receiving signals from the locating means for determining the location of the mobile transmitter/receiver within the communication system; data storage means for storing information relating to radio communication paths from all locations in the area to the fixed transmitters/receivers;
selecting means for determining from the location of the mobile transmitter/receiver determined by the location determining means and the information stored in the data storage means, a selected one of said communication paths; and conditioning means for providing the transmitting/receiving means with information stored in the data storage means relating to the selected communication path.
location determining means for receiving signals from the locating means for determining the location of the mobile transmitter/receiver within the communication system; data storage means for storing information relating to radio communication paths from all locations in the area to the fixed transmitters/receivers;
selecting means for determining from the location of the mobile transmitter/receiver determined by the location determining means and the information stored in the data storage means, a selected one of said communication paths; and conditioning means for providing the transmitting/receiving means with information stored in the data storage means relating to the selected communication path.
2. A mobile transmitter/receiver as claimed in Claim 1 wherein said conditioning means further comprises means for providing the transmitting/receiving means with power and/or sensitivity information from the data storage means relating to the selected communication path.
3. A mobile transmitter/receiver as claimed in Claim 1 or 2 including means for directing a radio beam from the transmitting/receiving means in accordance with information from the data storage means relating to the direction of the selected communication path.
4. A mobile transmitter/receiver as claimed in Claim 1 or 2 in which the data storage means includes a look-up table.
5. A communication system comprising: a plurality of fixed transmitters/receivers located at spaced apart positions in a terrestrial area, each fixed transmitter/receiver operating on one or more of a plurality of radio frequency channels; locating means;
and a plurality of mobile transmitters/receivers each comprising transmitting/receiving means for transmitting information to and receiving information from the fixed transmitters/receivers, location determining means for receiving signals from the locating means for determining the location of the mobile transmitter/receiver within the communication system, data storage means for storing information relating to radio communication paths from all locations in the area to the fixed transmitters/receivers, selecting means for determining from the location of the mobile transmitter/receiver determined by the location determining means and the information stored in the data storage means, a selected one or said communication paths, and conditioning means for providing the transmitting/receiving means with information stored in the data storage means relating to the selected communication path.
and a plurality of mobile transmitters/receivers each comprising transmitting/receiving means for transmitting information to and receiving information from the fixed transmitters/receivers, location determining means for receiving signals from the locating means for determining the location of the mobile transmitter/receiver within the communication system, data storage means for storing information relating to radio communication paths from all locations in the area to the fixed transmitters/receivers, selecting means for determining from the location of the mobile transmitter/receiver determined by the location determining means and the information stored in the data storage means, a selected one or said communication paths, and conditioning means for providing the transmitting/receiving means with information stored in the data storage means relating to the selected communication path.
Priority Applications (5)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| EP88304240A EP0292182B1 (en) | 1987-05-15 | 1988-05-11 | Mobile transmitter/receiver |
| JP63113720A JPS63299532A (en) | 1987-05-15 | 1988-05-12 | Moving transmitter and receiver and communication system |
| US07/193,826 US4907290A (en) | 1987-05-15 | 1988-05-13 | Mobile transmitter/receiver |
| AU28305/89A AU610968B2 (en) | 1987-05-15 | 1989-01-06 | Mobile transmitter/receiver |
| CA000588228A CA1327641C (en) | 1987-05-15 | 1989-01-13 | Mobile transmitter/receiver |
Applications Claiming Priority (3)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| GB878711490A GB8711490D0 (en) | 1987-05-15 | 1987-05-15 | Mobile transmitter/receiver |
| AU28305/89A AU610968B2 (en) | 1987-05-15 | 1989-01-06 | Mobile transmitter/receiver |
| CA000588228A CA1327641C (en) | 1987-05-15 | 1989-01-13 | Mobile transmitter/receiver |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA1327641C true CA1327641C (en) | 1994-03-08 |
Family
ID=27153156
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA000588228A Expired - Fee Related CA1327641C (en) | 1987-05-15 | 1989-01-13 | Mobile transmitter/receiver |
Country Status (5)
| Country | Link |
|---|---|
| US (1) | US4907290A (en) |
| EP (1) | EP0292182B1 (en) |
| JP (1) | JPS63299532A (en) |
| AU (1) | AU610968B2 (en) |
| CA (1) | CA1327641C (en) |
Families Citing this family (90)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| GB2234649B (en) * | 1989-04-27 | 1993-10-27 | Stc Plc | Personal communications systems |
| US5214789A (en) * | 1989-11-17 | 1993-05-25 | Uniden America Corporation | Radio channel allocation based on location of mobile users |
| SE466081B (en) * | 1990-04-26 | 1991-12-09 | Ericsson Telefon Ab L M | PROCEDURES FOR HANDOFFS IN A MOBILE RADIO SYSTEM |
| DE4017234A1 (en) * | 1990-05-29 | 1991-12-05 | Rohde & Schwarz | SYSTEM FOR ESTABLISHING LOS RADIO CONNECTIONS FROM MOBILE TRANSMITTER / RECEIVER STATIONS TO OTHER MOBILE OR STATIONAL COUNTERSTATIONS |
| US5043736B1 (en) * | 1990-07-27 | 1994-09-06 | Cae Link Corp | Cellular position location system |
| FR2669164B1 (en) * | 1990-11-14 | 1993-02-05 | Thomson Csf | METHOD FOR TRANSMITTING DATA BETWEEN MOBILE OR AUTONOMOUS VEHICLES. |
| US5734981A (en) * | 1991-01-17 | 1998-03-31 | Highwaymaster Communications, Inc. | Method and apparatus for call delivery to a mobile unit |
| US5155689A (en) * | 1991-01-17 | 1992-10-13 | By-Word Technologies, Inc. | Vehicle locating and communicating method and apparatus |
| US5105197A (en) * | 1991-03-12 | 1992-04-14 | Bell Atlantic Network Services, Inc. | Mobile access to telecommunications network |
| US5121126A (en) * | 1991-03-12 | 1992-06-09 | Bell Atlantic Network Services Inc. | Beacon enhanced telecommunications system and method |
| CA2068009C (en) * | 1991-08-19 | 1998-05-19 | Richard Norman Ames | System for decentralizing uplink network control and minimizing overhead in radio frequency data communications network |
| US5381444A (en) * | 1991-10-31 | 1995-01-10 | Fujitsu Limited | Radio environment measuring system |
| GB2261139B (en) * | 1991-11-04 | 1995-03-29 | Security Services Plc | Improvements in or relating to radio communication |
| CA2079827C (en) * | 1991-12-09 | 2003-08-19 | Theresa Chen Yen Wang | Mobile unit tracking system |
| US6324404B1 (en) * | 1991-12-26 | 2001-11-27 | Sycord Limited Partnership | Cellular telephone system that uses position of a mobile unit to make call management decisions |
| US5546445A (en) * | 1991-12-26 | 1996-08-13 | Dennison; Everett | Cellular telephone system that uses position of a mobile unit to make call management decisions |
| SG43096A1 (en) * | 1992-01-20 | 1997-10-17 | Nec Corp | Person location system |
| US5983108A (en) * | 1992-01-27 | 1999-11-09 | Highwaymaster Communications, Inc. | Method and apparatus for a nation-wide cellular telephone network |
| US6009330A (en) * | 1992-01-27 | 1999-12-28 | Highwaymaster Communications, Inc. | Method and apparatus for call delivery to a mobile unit |
| US5539810A (en) * | 1992-01-27 | 1996-07-23 | Highwaymaster Communications, Inc. | Data messaging in a communications network |
| US6295449B1 (en) | 1992-01-27 | 2001-09-25 | @Track Communications, Inc. | Data messaging in a communications network using a feature request |
| US5454027A (en) * | 1992-01-27 | 1995-09-26 | Hm Holding Corporation | Phantom mobile identification number method and apparatus |
| US5343512A (en) * | 1992-03-27 | 1994-08-30 | Motorola, Inc. | Call setup method for use with a network having mobile end users |
| US5218367A (en) * | 1992-06-01 | 1993-06-08 | Trackmobile | Vehicle tracking system |
| EP0582373B1 (en) * | 1992-07-17 | 1999-10-06 | Sun Microsystems, Inc. | Method and apparatus for implementing self-organization in a wireless local area network |
| EP0589552B1 (en) | 1992-09-08 | 2002-10-23 | Sun Microsystems, Inc. | Method and apparatus for maintaining connectivity of nodes in a wireless local area network |
| DE4232294A1 (en) * | 1992-09-28 | 1994-03-31 | Nord Systemtechnik | Control unit for radio systems |
| DE4307702A1 (en) * | 1993-03-11 | 1994-09-15 | Detecon Gmbh | A location-dependent handover method in mobile radio networks and device for carrying out the method |
| US5587715A (en) * | 1993-03-19 | 1996-12-24 | Gps Mobile, Inc. | Method and apparatus for tracking a moving object |
| US5517677A (en) * | 1993-05-13 | 1996-05-14 | Uniden America Corporation | Adaptive weighting of a scanning sequence |
| JP3109701B2 (en) * | 1993-08-17 | 2000-11-20 | キヤノン株式会社 | Communication device, information processing device having communication function, communication management device, and control method thereof |
| US5493694A (en) * | 1993-11-08 | 1996-02-20 | Trimble Navigation Limited | Fast response system for a fleet of vehicles |
| US5629693A (en) * | 1993-11-24 | 1997-05-13 | Trimble Navigation Limited | Clandestine location reporting by a missing vehicle |
| US5539924A (en) * | 1994-03-10 | 1996-07-23 | Motorola, Inc. | Method for providing communications within a geographic region |
| US5669061A (en) | 1994-08-19 | 1997-09-16 | Trimble Navigation Limited | Automatic cellular phone tracking |
| US5913170A (en) * | 1994-11-16 | 1999-06-15 | Highwaymaster Communications, Inc. | Locating system and method using a mobile communications network |
| US5724243A (en) * | 1995-02-10 | 1998-03-03 | Highwaymaster Communications, Inc. | Method and apparatus for determining expected time of arrival |
| US5699275A (en) * | 1995-04-12 | 1997-12-16 | Highwaymaster Communications, Inc. | System and method for remote patching of operating code located in a mobile unit |
| US5613217A (en) * | 1995-05-03 | 1997-03-18 | Telefonaktiebolaget Lm Ericsson | Transceiver site selection a cellular communications system |
| US5694322A (en) * | 1995-05-09 | 1997-12-02 | Highwaymaster Communications, Inc. | Method and apparatus for determining tax of a vehicle |
| DE19533113A1 (en) * | 1995-09-07 | 1997-03-13 | Siemens Ag | Device for measuring the signal transit time of a digital transmission device |
| GB2308946A (en) * | 1995-12-22 | 1997-07-09 | Spectronics Micro Syst Ltd | Channel Allocation for Registering in a Cellular Radio Network |
| US6477581B1 (en) * | 1996-04-09 | 2002-11-05 | International Business Machines Corporation | Location/motion sensitive computer connection |
| US5732358A (en) * | 1996-07-08 | 1998-03-24 | Motorola, Inc. | Method for selecting an optimal base transmitter in a radio communication system |
| US6029121A (en) * | 1997-08-22 | 2000-02-22 | Stashko; Stephen O. | Golf pin distance measuring system |
| JP3694396B2 (en) * | 1997-10-20 | 2005-09-14 | 松下電器産業株式会社 | Wireless communication apparatus and wireless communication method |
| US7092695B1 (en) * | 1998-03-19 | 2006-08-15 | Securealert, Inc. | Emergency phone with alternate number calling capability |
| DE19831086C2 (en) | 1998-07-10 | 2001-10-18 | Ericsson Telefon Ab L M | Telecommunication system |
| US20060241763A1 (en) * | 1998-08-03 | 2006-10-26 | Synthes (Usa) | Multipiece bone implant |
| US6269246B1 (en) | 1998-09-22 | 2001-07-31 | Ppm, Inc. | Location determination using RF fingerprinting |
| US6393294B1 (en) | 1998-09-22 | 2002-05-21 | Polaris Wireless, Inc. | Location determination using RF fingerprinting |
| JP2000197118A (en) * | 1998-12-24 | 2000-07-14 | Toshiba Corp | Radio communication device and method for setting specification of the radio communication device |
| EP1047275B1 (en) * | 1999-04-21 | 2005-11-02 | Motorola, Inc. | Apparatus and method for delivering data in a cellular communications network |
| US7330150B1 (en) | 1999-05-07 | 2008-02-12 | Garmin Corporation | Combined global positioning system receiver and radio |
| US6373430B1 (en) | 1999-05-07 | 2002-04-16 | Gamin Corporation | Combined global positioning system receiver and radio |
| US7196659B1 (en) | 1999-05-07 | 2007-03-27 | Garmin Corporation | Combined global positioning system receiver and radio |
| WO2002026536A2 (en) * | 2000-09-29 | 2002-04-04 | Varitek | Telematics system |
| FI116326B (en) * | 2000-12-27 | 2005-10-31 | Nokia Corp | Compact low profile magnetic feeder |
| US7266379B2 (en) * | 2001-05-30 | 2007-09-04 | Palm, Inc. | Resource location through location history |
| US7142900B1 (en) * | 2001-11-01 | 2006-11-28 | Garmin Ltd. | Combined global positioning system receiver and radio |
| US20030087602A1 (en) * | 2001-11-05 | 2003-05-08 | Palm, Inc. | Data prioritization and distribution limitation system and method |
| US20030104782A1 (en) * | 2001-11-30 | 2003-06-05 | Palm, Inc. | Object tagging system and method |
| US6985696B2 (en) * | 2001-12-20 | 2006-01-10 | Motorola, Inc. | Method and apparatus for facilitating wireless communications with a nonautomotive roaming object |
| US8601606B2 (en) | 2002-11-25 | 2013-12-03 | Carolyn W. Hafeman | Computer recovery or return |
| GB2414631B (en) * | 2004-05-26 | 2006-12-13 | Motorola Inc | A wireless communications network and method of operation thereof |
| US7908080B2 (en) | 2004-12-31 | 2011-03-15 | Google Inc. | Transportation routing |
| US7330122B2 (en) | 2005-08-10 | 2008-02-12 | Remotemdx, Inc. | Remote tracking and communication device |
| US7117075B1 (en) | 2005-08-15 | 2006-10-03 | Report On Board Llc | Driver activity and vehicle operation logging and reporting |
| US20070038338A1 (en) * | 2005-08-15 | 2007-02-15 | Larschan Bradley R | Driver activity and vehicle operation logging and reporting |
| US20070038351A1 (en) * | 2005-08-15 | 2007-02-15 | Larschan Bradley R | Driver activity and vehicle operation logging and reporting |
| US20070038353A1 (en) * | 2005-08-15 | 2007-02-15 | Larschan Bradley R | Driver activity and vehicle operation logging and reporting |
| US8626377B2 (en) | 2005-08-15 | 2014-01-07 | Innovative Global Systems, Llc | Method for data communication between a vehicle and fuel pump |
| US9818120B2 (en) | 2015-02-20 | 2017-11-14 | Innovative Global Systems, Llc | Automated at-the-pump system and method for managing vehicle fuel purchases |
| US7925320B2 (en) * | 2006-03-06 | 2011-04-12 | Garmin Switzerland Gmbh | Electronic device mount |
| US7737841B2 (en) * | 2006-07-14 | 2010-06-15 | Remotemdx | Alarm and alarm management system for remote tracking devices |
| US7936262B2 (en) | 2006-07-14 | 2011-05-03 | Securealert, Inc. | Remote tracking system with a dedicated monitoring center |
| US8797210B2 (en) * | 2006-07-14 | 2014-08-05 | Securealert, Inc. | Remote tracking device and a system and method for two-way voice communication between the device and a monitoring center |
| US9031583B2 (en) * | 2007-04-11 | 2015-05-12 | Qualcomm Incorporated | Notification on mobile device based on location of other mobile device |
| US20080254811A1 (en) | 2007-04-11 | 2008-10-16 | Palm, Inc. | System and method for monitoring locations of mobile devices |
| US9140552B2 (en) * | 2008-07-02 | 2015-09-22 | Qualcomm Incorporated | User defined names for displaying monitored location |
| US7899073B2 (en) | 2007-07-10 | 2011-03-01 | Qualcomm Incorporated | Methods and apparatus for monitoring for signals and selecting and/or using a communications band based on the monitoring results |
| US20090017838A1 (en) * | 2007-07-10 | 2009-01-15 | Qualcomm Incorporated | Methods and apparatus for selecting a communications band based on location information |
| US8705438B2 (en) | 2007-07-10 | 2014-04-22 | Qualcomm Incorporated | Methods and apparatus for selecting and/or using a communications band for peer to peer signaling |
| US9288751B2 (en) * | 2007-08-29 | 2016-03-15 | Qualcomm Incorporated | Use of position data to select wireless access point |
| MX2010009680A (en) | 2008-03-07 | 2011-02-23 | Securealert Inc | A system and method for monitoring individuals using a beacon and intelligent remote tracking device. |
| US8395547B2 (en) * | 2009-08-27 | 2013-03-12 | Hewlett-Packard Development Company, L.P. | Location tracking for mobile computing device |
| US8755815B2 (en) | 2010-08-31 | 2014-06-17 | Qualcomm Incorporated | Use of wireless access point ID for position determination |
| US20110237274A1 (en) * | 2010-03-25 | 2011-09-29 | Palm, Inc. | Mobile computing device having relative positioning circuit |
| US8514070B2 (en) | 2010-04-07 | 2013-08-20 | Securealert, Inc. | Tracking device incorporating enhanced security mounting strap |
| EP2622920B1 (en) | 2010-09-29 | 2024-01-17 | QUALCOMM Incorporated | Non-transient computer readable storage medium and mobile computing device employing matching of access point identifiers |
Family Cites Families (14)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US4222118A (en) * | 1978-07-31 | 1980-09-09 | The United States Of America As Represented By The Secretary Of The Navy | Intelligent automatic gain control circuit |
| DE2907611C2 (en) * | 1979-02-27 | 1981-04-23 | Licentia Patent-Verwaltungs-Gmbh, 6000 Frankfurt | Automatic receiver selection for radio control centers |
| DE2945852A1 (en) * | 1979-11-13 | 1981-05-21 | Siemens AG, 1000 Berlin und 8000 München | METHOD FOR DETECTING TRAFFIC IN A GUIDE AND INFORMATION SYSTEM FOR INDIVIDUAL TRAFFIC |
| JPH0619276B2 (en) * | 1981-08-17 | 1994-03-16 | 工業技術院長 | Portable map display device assembly |
| US4481670A (en) * | 1982-11-12 | 1984-11-06 | Motorola, Inc. | Method and apparatus for dynamically selecting transmitters for communications between a primary station and remote stations of a data communications system |
| US4550443A (en) * | 1982-11-12 | 1985-10-29 | Motorola, Inc. | Method and apparatus for dynamically selecting transmitters for communications between a primary station and remote stations of a data communications system |
| JPS59152739A (en) * | 1983-02-21 | 1984-08-31 | Hitachi Denshi Ltd | System for setting automatically antenna direction of radio base station |
| JPS59189730A (en) * | 1983-04-11 | 1984-10-27 | Nippon Denso Co Ltd | Controller of radio wave receiving direction for antenna of receiver of radio, television, or the like provided on moving object |
| JPS60261228A (en) * | 1984-06-08 | 1985-12-24 | Hitachi Ltd | Transceiver |
| ATE54398T1 (en) * | 1985-04-17 | 1990-07-15 | Siemens Ag | CELLULAR SYSTEM. |
| DE3516357C2 (en) * | 1985-05-07 | 1994-06-01 | Bosch Gmbh Robert | Radio telephone network for a radio area divided into radio cells and a mobile radio station |
| GB2176964B (en) * | 1985-06-26 | 1989-01-18 | Stc Plc | Integrated communications and navigation system |
| CA1282837C (en) * | 1987-03-20 | 1991-04-09 | Tetsuya Hanawa | Apparatus for selecting control channel in mobile communication system |
| JPS63261928A (en) * | 1987-04-20 | 1988-10-28 | Mazda Motor Corp | On-vehicle receiver |
-
1988
- 1988-05-11 EP EP88304240A patent/EP0292182B1/en not_active Expired - Lifetime
- 1988-05-12 JP JP63113720A patent/JPS63299532A/en active Pending
- 1988-05-13 US US07/193,826 patent/US4907290A/en not_active Expired - Lifetime
-
1989
- 1989-01-06 AU AU28305/89A patent/AU610968B2/en not_active Ceased
- 1989-01-13 CA CA000588228A patent/CA1327641C/en not_active Expired - Fee Related
Also Published As
| Publication number | Publication date |
|---|---|
| JPS63299532A (en) | 1988-12-07 |
| EP0292182B1 (en) | 1996-07-24 |
| EP0292182A2 (en) | 1988-11-23 |
| AU610968B2 (en) | 1991-05-30 |
| EP0292182A3 (en) | 1990-02-07 |
| AU2830589A (en) | 1990-07-12 |
| US4907290A (en) | 1990-03-06 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CA1327641C (en) | Mobile transmitter/receiver | |
| KR0168431B1 (en) | Mobile radio transmission system and a mobile station for use in the system | |
| US5214789A (en) | Radio channel allocation based on location of mobile users | |
| US4955082A (en) | Mobile communication system | |
| US5235633A (en) | Cellular telephone system that uses position of a mobile unit to make call management decisions | |
| AU748336B2 (en) | Cell identification based on distance | |
| US4144496A (en) | Mobile communication system and method employing frequency reuse within a geographical service area | |
| FI94693C (en) | Macro diversity using microcell type data transfer system | |
| US5815814A (en) | Cellular telephone system that uses position of a mobile unit to make call management decisions | |
| US6937877B2 (en) | Wireless communication with a mobile asset employing dynamic configuration of a software defined radio | |
| US5946611A (en) | Cellular telephone system that uses position of a mobile unit to make call management decisions | |
| US5659879A (en) | Method of covering shadow areas in a cellular mobile radio system and radio booster for implementing this method | |
| US5218716A (en) | Method for locating a communication unit within a multi mode communication system | |
| KR100310712B1 (en) | Method and apparatus for geographic based control in a communication system | |
| US5752197A (en) | Method for adjusting transmission power in a radio system, and an exchange | |
| US8103271B2 (en) | Aircraft data radio with alternative channel selection | |
| US6654362B1 (en) | Use of location in handoff in wireless communication systems | |
| EP0505106A2 (en) | Split service in cellular telecommunications networks and methods therefore | |
| FI108505B (en) | Device for identifying a terminal's connection with a network radio communication system comprising several networks | |
| US6002940A (en) | Mobile radio station | |
| CA2275723A1 (en) | Synchronisation of base stations in a cellular telecommunications system | |
| CA1061412A (en) | Mobile communication system and method employing directional service area coverage | |
| KR20050054953A (en) | Method for operating a mobile radio telephone system, mobile radio telephone system, mobile station and device for determining a sub-group of adjacent radio cells in a mobile radio telephone system | |
| EP1013121B1 (en) | Method for determining radio network hot spot area location, and transceiver | |
| JP4168508B2 (en) | Radio communication system and radio communication apparatus for mobile station used therefor |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| MKLA | Lapsed |